Battery Bank

[Darkspeed]

Bruce, this is basically a high amperage switch ( 200A ) and it uses 12v from a small switch ( or ignition power ) to close it. They are very useful for connecting battery banks of the same voltage as long as the alternator / generator is putting out less than 200A in to a dead battery bank and the voltage differential between the two battery banks you are connecting does not result in over 200A of equalization. > http://www.ebay.com/itm/TE-Electronics-Kilovac-Czonka-III-High-Voltage-Relay-EV200AAANA-/261734158612?pt=LH_DefaultDomain_0&hash=item3cf0925114

[gumpy]

If you are going to remove the over-the-road air (not my recommendation, but many do), you have a solenoid in there that will work perfectly for a crossover.

Again, though, both battery banks need to be the same voltage. Your bus is 24v.

[TomC]

My crossover is-I bought 2-150amp continuous rated solenoids (look like Ford starting solenoids {or should they be called a relay?}). Strapped them together to equal the 300amp output of my alternator. It is wired in between the starting and house batteries. It serves two purposes. One to charge my house batteries going down the road. Two, if the starting batteries are dead, can start on the house batteries. I have a simple on-off-on switch on the dash. Off is not activated. On is activated through the ignition switch. The other On is wired through the house batteries to activate if the starting batteries are dead. Simple, effective, and has worked for over 20 years. The key is to buy continuous rated solenoids. Good Luck, TomC

[Iceni John]

Another option for the House/Chassis intertie is to use the Blue Sea marine battery isolator switches.   They're good quality, very reasonably priced (except at marine outfitters!), and can handle 350 amps continuous and many times more than that intermittently.   I have two separate House battery banks with a pair of those Blue Sea switches to connect them to the starter.   For the negative I use the normal 9001 switch, but for the positive I use the 9002 which has an extra pair of switched terminals for an indicator lamp  -  if the House batteries are connected to the Chassis system a green warning lamp on my dash switch panel lights up.   And in case you're wondering why I have a separate switch for the House negatives, I have a 300A Class T catastrophe fuse on each House bank's negative, and to avoid the risk of blowing these expensive fuses if starting the engine from the House batteries I decided to bypass those fuses with a negative switch directly to the starter.   This setup is simple, cheap and hopefully 100% reliable  -  Blue Sea makes good switches for bus electrical systems.

John